Also called the Sorbello Well, named after the noble family that owned the palace overhead, this monument is an extraordinary feat of hydraulic engineering. Dating back to the second half of the 3rd century, it testifies to Perugia's highly advanced civilization at the time.

The size of the well, which was much larger than the water reservoirs that commonly existed in the Etruscan age, has led historians to believe that it was originally built as a cistern.

From a Medieval underground passageway, visitors can enter and pass through the well on a modern walkway that reveals the imposing depth of this monument.

Letters etched into the base of the well's exterior - or so-called "quarry signs" - are similar to those found on various blocks in the city walls.